Find employee tenure for a company - sql

Question

I have written the following query to get the employees tenure yearwise.
Ie. grouped by "less than 1 year", "1-2 years", "2-3 years" and "greater than 3 years".
To get this, I compare with employee staffed end_date.
But I am not able to get the correct result when comparing with staffed end_date.
I have pasted the complete code below, but the count I am getting is not correct.
Some employee who worked for more than 2 years is falling under <1 year column.
DECLARE #Project_Id Varchar(10)='ITS-004275';
With Cte_Dates(Period,End_date,Start_date,Project_Id)
As
(
SELECT '<1 Year' AS Period, GETDATE() AS End_Date,DATEADD(YY,-1,GETDATE()) AS Start_date,#Project_Id AS Project_Id
UNION
SELECT '1-2 Years', DATEADD(YY,-1,GETDATE()),DATEADD(YY,-2,GETDATE()),#Project_Id
UNION
SELECT '2-3 Years', DATEADD(YY,-2,GETDATE()),DATEADD(YY,-3,GETDATE()),#Project_Id
UNION
SELECT '>3 Years', DATEADD(YY,-3,GETDATE()),'',#Project_Id
),
--select * from Cte_Dates
--ORDER BY Start_date DESC
Cte_Staffing(PROJECT_ID,EMP_ID,END_DATE) AS
(
SELECT FK_Project_ID,EMP_ID,MAX(End_Date)AS END_DATE FROM DP_Project_Staffing
WHERE FK_Project_ID=#Project_Id
GROUP BY FK_Project_ID,Emp_ID
)
SELECT D.PROJECT_ID,D.Start_date,D.End_date,COUNT(S.EMP_ID) AS Count,D.Period
FROM Cte_Staffing S
RIGHT JOIN Cte_Dates D
ON D.Project_Id=S.PROJECT_ID
AND S.END_DATE<D.End_date AND S.END_DATE>D.Start_date
GROUP BY D.PROJECT_ID,D.Start_date,D.End_date,D.Period

Answer 1

i think this will solve the problem
as you can see, you should use is like this:
DATEADD(year, -1, GETDATE())
you should also get the GETDATE() to a parameter

Answer 2

I find your query logic a little bit messy. Why don't you just compute the total period for every employee and use CASE clause? I can help you with code if you'll give me DP_Project_Staffing table structure. Do you have begin_date field in it?

Answer 3

You are taking the MAX(End_date) of the CTE staffing table. In that case, when an employee has several entries, only the most recent will apply. You want to use MIN instead.
Like this:
Cte_Staffing(PROJECT_ID,EMP_ID,END_DATE) AS
(
SELECT FK_Project_ID, EMP_ID, MIN(End_Date)AS END_DATE
FROM DP_Project_Staffing
...
Re-reading your question, you probably don't want the staffing end_date for tenure calculation; you'd want to use the start_date. (Or whatever the column is called in DP_Project_Staffing)
I would also change the WHERE/JOIN clause to be inclusive on one of the sides, so you have either
AND S.END_DATE <= D.End_date AND S.END_DATE > D.Start_date
or
AND S.END_DATE < D.End_date AND S.END_DATE >= D.Start_date
Since you are using miliseconds in the date-comparison it won't make any difference in this case. However, should you change the granularity to be only the date, which would make more sense, you would lose all records where the employee started exactly 1 year, 2 years, etc. ago.

Answer 4

SELECT FK_Project_ID,E.Emp_ID,MIN(Start_Date) AS Emp_Start_Date ,MAX(End_Date) AS Emp_End_Date,
E.Competency,E.First_Name+' '+E.Last_Name+' ('+E.Emp_Id+')' as Name,'Period'=
CASE
WHEN DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))<=12 THEN '<1 Year'
WHEN DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))>12 AND DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))<=24 THEN '1-2 Years'
WHEN DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))>24 AND DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))<=36 THEN '2-3 Years'
WHEN DATEDIFF(MONTH,MIN(Start_Date),MAX(End_Date))>36 THEN '>3 Years'
ELSE 'NA'
END
FROM DP_Project_Staffing PS
LEFT OUTER JOIN DP_Ext_Emp_Master E
ON E.Emp_Id=PS.Emp_ID
WHERE FK_Project_ID=#PROJ_ID
GROUP BY FK_Project_ID,E.Emp_ID,E.Competency,First_Name,Last_Name